Please help if i don't pass I'm done

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

In a sample of 200 residents of georgetown county, 120 reported they believed the county real estate taxes were too high. develop a 95 percent confidence interval for the proportion of residents who believe the tax rate is too high. (round your answers to 3 decimal places.) confidence interval for the proportion of residents is up to . would it be reasonable to conclude that the majority of the taxpayers feel that the taxes are too high?

Solve x+3y=6 and 4x-6y=6 by elimination . show work !